Introduction Middle meningeal artery (MMA) embolization is becoming an increasingly established treatment option for chronic subdural hematoma (cSDH). Although several systematic reviews have considered outcomes and/or overall incidence of complications following MMA embolization, no prior review has conducted a comprehensive assessment of overall and specific complications following MMA embolization. The aim of the present systematic review was to establish estimates of incidence for overall and specific complications following MMA embolization.

Methods PubMed, Embase and Cochrane were searched for studies reporting complications following MMA embolization in November 2022. Studies with >5 adult patients undergoing MMA embolization for cSDH were included. Outcomes were categorized according to complication type, including neurological complications, cardiovascular complications, infection, and miscellaneous complications. PRISMA guidelines were followed.

Results A total 389 abstracts were screened of which 128 full texts were reviewed. A final 49 studies containing 3009 patients undergoing MMA embolization were included. No complications or mortalities were reported in 28 studies representing 1352 patients. Across the 49 studies, the incidence of overall complications was 3.79% (114/3009 patients).

Neurological complications were reported in 40 patients (1.33%) including: new onset seizures in 13 patients (0.43%); unspecified stroke in 9 patients (0.30%); aphasia in 4 patients (0.13%); MMA rupture in 4 patients (0.13%); visual changes in 3 patients (0.10%); facial droop in two patients (0.07%); lethargy in one patient (0.03%); imbalance in one patient (0.03%); numbness in one patient (0.03%); headaches in one patient (0.03%); and hemiplegia in one patient (0.03%). Cardiovascular complications were reported in 8 patients (0.27%) including: deep venous thrombosis or pulmonary embolus in two patients (0.07%); fistula in two patients (0.07%); access site hematoma in one patient (0.03%); aortic dissection in one patient (0.03%); femoral artery pseudoaneurysm in one patient (0.03%); and external carotid artery spasm in one patient (0.03%). Infection was reported in 11 patients (0.37%) including: urinary tract infection in three patients (0.10%); pneumonia in three patients (0.10%); and empyema in three patients (0.10%). Other complications reported included: acute kidney injury in three patients (0.10%); catheter herniation in two patients (0.07%); and retained microcatheter in one patient (0.03%). No periprocedural mortalities were reported.

Conclusion The published literature suggests that MMA embolization is a generally well-tolerated procedure, but with a low risk of significant complications, including, but not limited to stroke, seizures, visual obscurations, and facial palsy. Further studies and sub-analyses are needed to fully characterize the incidence of such complications.

Disclosures J. Gerstl: None. M. Shafi: None. S. Badikol: None. N. Nawabi: None. R. Mekary: None. M. Sukumaran: None. A. Kappel: None. A. Feroze: None. T. Smith: None. M. Aziz-Sultan: None.